ltsp-build-client failed

[davidsxls]

I followed https://wiki.ubuntu.com/UbuntuLTSP/LTSPQuickInstall.
Both ltsp-server-standalone and openssh-server has been installed successfully.
DHCP server configured and tested.

When I executed $sudo ltsp-build-client, I got:

I: Retrieving Release
E: Failed getting release file http://archive.ubuntu.com/ubuntu/dists/dapper/Release

so I check the URL:
$wget --spider http://archive.ubuntu.com/ubuntu/dists/dapper/Release
--11:00:44-- http://archive.ubuntu.com/ubuntu/dists/dapper/Release
=> `Release'
Resolving archive.ubuntu.com... 82.211.81.151, 82.211.81.182
Connecting to archive.ubuntu.com|82.211.81.151|:80... connected.
HTTP request sent, awaiting response...
HTTP/1.0 200 OK
Date: Tue, 25 Jul 2006 13:54:26 GMT
Server: Apache/2.0.55 (Ubuntu)
Last-Modified: Wed, 31 May 2006 18:59:08 GMT
ETag: "c14544-87be-4151a256bd700"
Accept-Ranges: bytes
Content-Length: 34750
Content-Type: text/plain; charset=UTF-8
Age: 50773
X-Cache: HIT from squid
Via: 1.0 squid:80 (squid/2.6.STABLE1-20060724)
Connection: close
Length: 34,750 (34K) [text/plain]
200 OK

This post might be related to my problem, http://www.ubuntuforums.org/showthread.php?t=82053.

I have 3 NIC:
eth0 - internet
eth1+eth2 - bridged as br0, LAN
The network are configured and work perfectly.

What should I do to get ltsp-build-client working?

TIA